Water Pump User Manual

Pump delivers insufficient flow rate Motor is overloaded Pump is running, but does not deliver Excessive bearing temperature Leakage at the pump Excessive leakage at the shaft seal Vibrations during pump operation Excessive rise of temperature inside the pump
Multitec
26
8 Trouble-shooting
Cause Remedy
1)
* * *
Pump delivers against an ex cessively high discharge pressure. Re-adjust to duty point.
Check plant for impurities.
Fit one or several larger impell ers.
Increase the speed (turbine, I.C. engine).
* * * *
Pump or piping are not compl etely vented or primed. Vent and/or prime.
* *
Supply line or impeller clogged. Remove deposits in the pump and/or piping.
* *
Formation of air pockets in the piping. Alter piping lay out.
Fit a vent v alve.
* * * * *
Suction head is too hi gh / NPSH
available
(positiv e s uction head) is too low. Check /alter l iquid lev el.
Fully open shut-off valve in the suc tion line.
Change suction line, if the friction losses in the s uction line are too high.
Check suction strainer/foot v alve and suction line for clogging.
* *
Air i ntake at the shaft seal. Clean barrier liquid duct, supply external barrier liquid, i f necessary
2) 3)
,or
increase its pressure.
Fit new shaft s eal.
* * *
Wrong direction of rotation. Interchange two of the phases of the power suppl y cable.
*
Speed is too low.
2)
Increase speed.
* * * *
Wear of internal pump parts. Replac e worn components by new ones.
* *
Pump back pressure is lower than speci fied in the purchase order. Adjust duty point ac curately.
* *
Density or viscosity of the fluid pumped is higher than stated in the pur-
chase order.
2)
* * *
Gland cover too tight or askew. Correct. Increase leakage slightly.
*
Speed is too high. Reduce speed.
2)
*
Tie bolts / gaskets Tighten the bolts.
Fit new gaskets.
*
Worn shaft seal. Fit new shaft s eal.
Check barrier liquid pressure
2) 3)
*
Score marks or roughness on shaft protecting sleeve / shaft sleeve. Replace shaft protecting sleeve / shaft sleev e.
Fit new shaft s eal.
*
Vibrations during pump operation Improve suction conditions.
Re-align the pump.
Re-balance the impell er.
Increase pressure at the pump suction nozzle.
* * *
The unit is misaligned. Re-align.
* * *
Pump is warped or sympathetic vibrations i n the piping. Check pipel ine connections and secure fixing of pump; if required, reduce
the distances between the pipe clamps.
Fix the pipelines using anti-vibration material.
*
Outer bearing races of fixed bearing are loose. Clamp outer bearing races axially.
*
Increased axial thrust.
2)
Check rotor clearances, axial adjustment and clearance on throttling bush
/ balance drum.
* *
Insuffic ient or exc essive quantity of lubric ant or unsui table lubricant. Top up, reduce or change lubricant.
*
Non-compliance with specified coupling distance. Correct distanc e according to the general arrangement drawing.
* *
Motor is running on two phases only. Repl ace the defec tive fuse.
Check the electric cable connecti ons.
* * *
Rotor is out of balance. Clean the impellers.
Re-balance the impell er.
* * *
Defective bearing(s). Fit new bearing(s).
* * *
Insufficient rate of flow. Increase the minimum rate of flow.
*
Incorrect inflow of circulation l iquid. Increase the free cross-section.
* * * *
In case of parallel operation, check valve defectiv e or missing. Check.
*
Incorrect installation of gland packing,
unsuitabl e packing material
Check.
* * *
Inadequate cooling of shaft seal chamber Check the free cross-section of the cooling liquid feed line.
* * *
Change in the free cross-section of the return line of the balanci ng liquid
Wear in balancing device
Check the balancing line.
Check throttling bus h / balance drum clearances.
1) Pump pressure must be released before attempting to remedy faults on parts whi ch are subjected to pressure.
2) Contact KSB
3) Pump version with barrier liquid supply on request only